Kyle Fuerschbach, Kevin P. Thompson, and Jannick P. Rolland
We report on the surface figure measurement of a freeform, ?φ-polynomial (Zernike) mirror for use in an off-axis, reflective imaging system. The measurement utilizes an interferometric null configuration that is a combination of subsystems each addressing a specific aberration type, namely, spherical aberration, astigmatism, and coma.